1. Field of the Invention
This invention relates to novel sulfur-containing organopolysiloxanes, to compositions including such polymers and to siloxane elastomers containing sulfur.
2. Description of the Prior Art
Organopolysiloxanes in which the terminal silicon atoms have one or more alkoxy groups attached thereto are known in the art and are useful in the preparation of compositions which are capable of being cured at room temperature to produce rubbery siloxane materials. The preparation of organopolysiloxanes in which terminal silicon atoms have at least two alkoxy groups attached thereto may be prepared, for example, according to the procedure set forth in U.S. Pat. No. 3,161,614. The reference also discloses the preparation of curable compositions including such polymers and curing catalysts such as metal salts of carboxylic acids, titanium esters and amines. As another example, it is noted in U.S. Pat. No. 3,294,729 that mixtures of alkoxy substituted silanes with hydroxylated siloxanes and selected titanium compounds will cure to an elastomeric material upon exposure to atmospheric moisture. It is proposed in U.S. Pat. No. 3,161,614 that the alkoxyl groups of the silane react with the hydroxyl groups of the hydroxylated siloxane to produce alkoxy ended siloxanes which, in turn, are cured to elastomers upon exposure to atmospheric moisture by the action of the catalyst.
It is believed that one of the limiting factors on storage stability of room temperature curable mixtures of alkoxy endblocked siloxane polymers and catalysts is the limited stability of, e.g, methyldimethoxy and trimethoxy siloxy groups at the ends of siloxane polymers.
There exists a need in the art for alkoxy functional group-containing polysiloxanes that exhibit storage stability in the presence of curing catalysts.